Sphygmomanometers are pressure measuring devices that are used to measure the arterial blood pressure of a patent. These devices typically include a pneumatic bulb, which inflates an interior pressure chamber of an attached cuff/sleeve that is fitted over a limb of the patient. A diaphragm or bellows assembly. responsive to changes in fluid pressure of the pneumatic bulb and the interior pressure chamber of the sleeve, is positioned in the housing of a gage (i.e., a gage housing), which is fluidly connected to the interior pressure chamber of the cuff.
The connection between the gage housing and the interior of the inflatable cuff generally occurs by connecting a section of elongated hose or tubing extending from the cuff to an inlet port that is disposed on one end of the gage housing. It is currently preferred to effect such a connection through use of a so-called “quick connect” arrangement. A quick connect arrangement is advantageous for several reasons, including the utilization of a minimum of connection parts, and because this form of connection enables a cuff to remain fitted over a limb of a patient, thus providing the patient with freedom of movement while still allowing for a blood pressure measurement to be taken, when necessary, by quickly connecting the cuff to a gage housing or other suitable apparatus.
A typical luer lock “quick-connect” fitting 10, as would extend from an inlet port of certain gage housings, is shown in FIGS. 1A and 1B. This fitting 10 includes an open connection end 20 having an internal luer thread 30 surrounding a cylindrical male connection element 40. The design of this type of fitting 10 (hereinafter referred to as a “male fitting”) is advantageous in that it enables simple, yet reliable connection of the connection end 20 to a female luer lock (not shown), which is defined within or extending from a cuff.
Unfortunately, however, there are drawbacks directly related to the use of these types of male fittings 10. Most notably, because female luer locks are commonly utilized to connect various medical devices and equipment, their design can enable several different types of male fittings to be connected thereto, including those of unrelated devices and equipment. For example, based on its design, the female luer lock used to interconnect a patient's intravenous (IV) line to the male fitting at the end of IV drip can also be connected to the male fitting 10 shown in FIGS. 1A and 1B. This interconnection is problematic because if for some reason (e.g., untrained personnel, chaos) a connection were to occur between the male fitting 10 and the female luer lock of a patient's IV line, air could enter the patient's bloodstream and could potentially cause moderate to severe complications to the patient's health.
One solution to this design dilemma, as adopted in places such as Europe, has been to mandate that blood pressure measurement gages not be equipped with male fittings such as the FIGS. 1A and 1B fitting 10. Instead, it is common in these places to manufacture measurement gages that include a female fitting 50, such as shown in FIG. 2, in lieu of a male fitting. The female fitting 50 is designed to include internal threading 60 and an internal width 70, each of which are incompatible with female luer locks.
Thus, due to its design, incorporation of the female fitting 50 of FIG. 2 within blood pressure measurement systems beneficially prevents the occurrence of inadvertent—and potentially dangerous—connections between the male fitting 10 of FIG. 1 and the female luer lock provided on other medical devices and/or equipment (e.g., an IV line). At the same time, however, the incorporation of female luer locks to effect fluid connection between a cuff and a male fitting 10 disadvantageously renders thousands of existing cuffs that are still in circulation in the United States and worldwide obsolete. Consequently, manufacturers either: (a) provide gage housings that incorporate a male fitting 10, as shown in FIGS. 1A and 1B, whereby they must forgo the marketplace in countries that do not allow female luer lock quick-connect fittings and wherein these companies risk the above-described safety issues, or (b) provide gage housings that incorporate female fittings 50, as shown in FIG. 2. Doing the latter, manufacturers avoid the safety problem associated with the male fittings 10 of FIGS. 1A and 1B, but the resulting gage is incompatible with the female luer locks present on existing gage housings that are designed to accept the male fitting. Manufaturers could do both (a) and (b) options, but this is not optimal from either a economic or marketing standpoint.
Thus, there is a need for a device that can provide interchangeable connections between a blood pressure measurement cuff and gage housings that may include other male or female fittings, yet which does not encounter safety issues and is not unduly complex to design, to produce or to use in practice.